When the weather starts to cool off, you are probably concerned about how you’ll take full advantage of your heating and cooling. After all, HVAC costs routinely add up to a big portion of your monthly electric bill. To figure out new ways to reduce costs, some people take a closer look at their thermostat. Could there be a setting they can use to increase efficiency?
The bulk of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a typical cycle, what can the fan setting provide for your HVAC system? This guide will help. We’ll walk through just what the fan setting is and when you can use it to reduce costs in the summer or winter.
What Is the Fan Setting on My Thermostat?
For the majority of thermostats, the fan setting indicates that the air handler’s blower fan remains on. Some furnaces will run at a low level with this setting, but in general heating or cooling isn’t being made. The ‘Auto’ setting, conversely, will turn on the fan over a heating or cooling cycle and switch it off once the cycle is complete.
There are advantages and disadvantages to switching on the fan setting on your thermostat, and whether you do or don’t should depend on your distinct comfort needs.
Advantages to trying the Fan/On setting:
- You can keep the temperature throughout your home more uniform by allowing the fan to keep generating airflow.
- Indoor air quality can increase since continuous airflow will keep moving airborne particles into the air filter.
- Fewer start-stop cycles for the system's fan helps extend its life span. Because the air handler is usually part of the furnace, this means you can avoid needing furnace repair.
Downsides to switching to the Fan/On setting:
- A constant fan will likely raise your energy expenses somewhat.
- Nonstop airflow may clog your air filter up more quickly, increasing the frequency you’ll need to replace it.
Should My Thermostat Be on Fan or Auto in Summer/Winter
Through the summer, warm air will sometimes persist in unfinished spaces such as the attic or an attached garage. If you leave the fan on, your HVAC system can draw this warm air into the rest of your home, pushing the HVAC system to work more to keep up with the preferred temperature. In severe heat, this may lead to needing AC repair more quickly as wear and tear increases.
The opposite can take place during the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually flow into the rest of your home. Leaving the fan running will sometimes pump more cold air upward, increasing the amount of heating you need to stay warm.
If you’re still trying to figure out if you should use the fan/on setting, don’t forget that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on may work for you if:
Someone in your household has allergies. Allergies and other respiratory conditions can be stressful on the family. Leaving the fan on should help to enhance indoor air quality, helping your family breathe easier.
Your home deals with hot and cold spots. Lots of homes deal with difficult hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting can help limit these changes by consistently refreshing each room’s airflow.